Project-Based Invoice Template Canada — Fixed-Fee Freelance Billing
Fixed-price project billing offers clarity for both you and your client — the price is agreed upfront, and there are no surprises when the invoice arrives. But a fixed-fee invoice needs to be carefully structured to protect you from scope creep, ensure milestones are tied to deliverables, and clearly apply GST/HST to the agreed amount.
Fixed-Price vs. Time and Materials
In a fixed-price (project-based) engagement, you agree on a total price for a defined scope of work. You bear the risk if the project takes longer than expected, but you also benefit if you finish efficiently. This model works well when the scope is clear and unlikely to change.
In a time and materials (T&M) engagement, you bill for hours worked plus any reimbursable expenses. The client bears the risk of cost overruns if the project expands. See our hourly rate invoice template for T&M billing.
How to Structure a Project Invoice with Milestone Breakdown
Rather than a single large invoice at project completion, break the project into milestones. Each milestone invoice is triggered by the completion and approval of a specific deliverable. A typical three-milestone structure:
- Milestone 1 — Project kickoff (30%): Paid upfront or upon scope sign-off. Covers your time to start and ensures the client is committed.
- Milestone 2 — Draft delivery (40%): Paid when you deliver the draft or beta version for client review.
- Milestone 3 — Final delivery (30%): Paid upon final approval and handover of all files.
Example: Project Invoice — Website Design (Ontario)
| Description | Amount |
|---|---|
| Project: TechStart Inc. — 5-page WordPress website Total Contract Value: $4,500 | |
| Milestone 2 of 3 — Design mockups approved, development complete Deliverables: Home, About, Services, Blog, Contact pages. Responsive, mobile-first. | $1,800.00 |
| Change Order CO-2026-001 (approved Feb 28, 2026): Add team gallery page | $350.00 |
| Subtotal | $2,150.00 |
| HST 13% (BN: 334455667 RT0001) | $279.50 |
| Total Due (Milestone 2) — Due March 17, 2026 | $2,429.50 |
Deliverables List
Always list exactly what is being delivered with each milestone. Vague descriptions like "website work" lead to disputes. Specific deliverables like "5-page WordPress website (Home, About, Services, Blog, Contact), responsive design, staging environment delivered for review at [URL]" are unambiguous.
Change Order Language
Scope creep is the enemy of fixed-price projects. Protect yourself with clear change order language in your contract and on your invoices:
"Work outside the original project scope requires a written change order approved by both parties before work commences. Change orders are billed at $120/hour or as a flat fee as agreed in writing."
GST/HST on Fixed-Fee Work
GST/HST applies to the total fixed fee, including change orders. Apply the appropriate rate for the province where your client is located. If you collect a deposit under a project contract, you must also apply GST/HST to the deposit amount at the time it is collected.
Related Templates
- Hourly Rate Invoice Template — time and materials alternative
- Deposit Invoice Template — request upfront payment before starting
- Consultant Invoice Template — milestone billing for consulting projects
- Contractor Invoice Template — progress billing for construction projects